This invention relates to a catalyst bed assembly. More particularly, this invention relates to a catalyst bed assembly used in a rocket propulsion system.
FIG. 1 is a schematic of a rocket propulsion system 100. The system 100 includes a rocket engine 101. A fuel pump 103 supplies fuel to the rocket engine 101 from a fuel supply 105. Likewise, an oxidizer pump 107 supplies oxidizer to the rocket engine from an oxidizer supply 109. The rocket engine 101 combines the fuel and oxidizer, and ignites the mixture in a combustion chamber (not shown). The exhaust 111 exits a nozzle (not shown) to produce thrust.
To provide the amount of fuel and oxidizer required by the rocket engine 101, pumps 103, 107 are preferably turbopumps. FIG. 2 is a schematic of a turbopump assembly 107. Generally speaking, the turbopump assembly 107 includes a turbine 113 connected to an impeller 115 by a shaft 117. The turbine 113 converts the kinetic energy from an exhaust stream 119 into shaft horsepower to drive the impeller 115. The impeller 115 transports the oxidizer from the supply 109 to the rocket engine 101. Turbopump 103 for the fuel operates in a similar manner, and is not described in further detail.
In a rocket propulsion system using kerosene as the fuel and hydrogen peroxide as the oxidizer, the exhaust stream 119 that is used to drive the turbopump 107 can be created by a catalyst bed assembly which converts the hydrogen peroxide into oxygen and water vapor. The conversion of hydrogen peroxide also generates heat. In previous propulsion systems, which used less pure (e.g. a lower wt-%) hydrogen peroxide, the management of the heat produced by such conversion was not a major concern.
Future rocket propulsion systems, however, plan to use higher purity (e.g. greater wt-%) hydrogen peroxide. As the concentration of hydrogen peroxide increases, the heat generated during the decomposition of hydrogen peroxide into water vapor and oxygen also increases. As an example, conversion of concentrate (98 wt-%) hydrogen peroxide can generate temperatures of approximately 2192xc2x0 R. Clearly, thermal management of this increased heat becomes a concern. The catalyst bed assemblies used in these systems must be designed to withstand the increased heat.
However, the techniques used to manage the increased heat in the catalyst bed assembly should not significantly affect other aspects of the system. For example, the catalyst bed assembly design should keep weight to a minimum. Preferably, the catalyst bed assembly should be designed without a need for cooling lines. The catalyst bed design should also avoid complexity.
It is an object of the present invention to provide a new and improved catalyst bed assembly.
It is a further object of the present invention to provide a catalyst bed assembly capable of managing higher temperatures.
It is a further object of the present invention to provide a relatively lightweight catalyst bed assembly.
It is a further object of the present invention to provide a relatively non-complex catalyst bed assembly.
These and other objects of the present invention are achieved in one aspect by a catalyst bed assembly. The catalyst bed assembly includes: an outer housing having an open interior, an inlet leading to the open interior, and an outlet from the open interior; a catalyst bed in the open interior; and a gap between the outer housing and the catalyst bed. The open interior receives a material from the inlet. A portion of the material enters the catalyst bed to expose the material to a catalyst so that the material and the catalyst react and create heat within the catalyst bed assembly. A remainder of the material enters the gap between the outer housing and the catalyst bed to cool the catalyst bed assembly.
These and other objects of the present invention are achieved in another aspect by a turbopump assembly. The turbopump assembly includes a catalyst bed assembly, a nozzle, a turbine and a pump. The catalyst bed assembly includes: an outer housing having an open interior, an inlet leading to the open interior, and an outlet from the open interior; a catalyst bed in the open interior of the container; and a gap between the outer housing and the catalyst bed. The nozzle is located downstream of the outlet. The turbine is located downstream of the nozzle. The turbine drives the pump. The open interior receives a material from the inlet. A portion of the material can enter the catalyst bed to expose the material to a catalyst so that the material and the catalyst react and create heat within the catalyst bed assembly. A remainder of the material can enter the gap between the outer housing and the catalyst bed to cool the catalyst bed assembly.
These and other objects of the present invention are achieved in another aspect by a method of cooling a catalyst bed assembly. The method includes the steps of: providing a gap between an outer housing and a catalyst bed; and introducing material into the gap between the outer housing and the catalyst bed to cool the catalyst bed assembly.